Filter



Feb. 25, 1936. R. N. BURCKHALTER ETAL 2,031,589

. FILTER Filed July'll, 1932 2 Sheets-Sheet 1 2 f7' j jf" 2 22 21 4Z R.N. BURCKHALTER ET AL FILTER Feb. 25, 1936.

Filed July 11, 19152 2 Sheets-Sheet 2 Patented Feb. 25, 1936 UNITEDSTATES PATENT OFFICE mma mmm Nash Bmkhauer and 'James Marshall Osburn,Michigan City, Ind., assgnors to Michlana Products .Corporatom MichiganCity, Ind., a. corporation of Indiana Application July' 11, 1932, SerialNo. 621,905

Claims.

-Fig. 1 is an elevation o f the complete lter' mounted on theY crankcase of an engine;

Fig. 2 is a vertical section taken on the line 2 2 of Fig. 1;-

Fig. -3 is a. transverse Asection villustrating one step in themanufacture of the illter element PrOPel';

Fig. 4 is a plan viewl of a blank used in makln the filter elementproper; y

But these drawings and the corresponding specic description are used forthe purposej of illustration and disclosure, and are not intended toimpose limitations on the claims.

The lter casing -includes a shell I0 about 54%" outside diameter drawnfrom 12 gauge sheet steel, the lower end of which nts in a groove Il inthe top of a base casting l2 of aluminum, cast iron, or the like. Thiscasting is substantially in the form of a cup having a. machined face|3,' at one side extended by ilanges |4'to receive bolts I5 for mountingthe lter on the crank case IG,

or other place that it is to be used. 'I'here is an integral projectionIl extending inwardly from the machined face and provided with a.threaded bore I8 aligned with the axis of the shell l0, to

receive the lower threaded end of the tube I9, l-" outside diameter, andf'g" inside diameter, which has-a numberof relatively large perforations20 along the intermediate portion of its length, and is threaded at thetop 2| to receive a, cap nut y22 by which the shell l0 is made fast tothe base. The tube I9 is locked to the 'base casting by a. nut 45l?.

' The base is bored horizontally at 24 and vertically at 25 to form aninlet passage which is extended upwardly by tube 26 to a point above thetop of the base casting, whereby substantially lthe entire interior ofthe base is made available as a sump, or collecting chamber 26 forforeign matter intercepted by the screen, and commonlycalled sludge. y

The base is also bored horizontally at 21 to the lower end of the boreI8 forming an outlet PaSSge.

' from the inner flanges 48 and 49, and they are (Cl. Zlib-'165)drops,'many engineers require a by-pass for all lter installations, sothat the bearings may not be starved by tardy ilow of cold oil throughthe lter. To'meet this requirement the outlet and inlet are connected bya by-pass 28 in the `form 5 of a vertical bore in the base casting whichis normally closed by a ball 29, held against a. seat 30 by a spring 3lcompressed by a. nut 32.

As thus far described, the structure is well known and has been selectedto illustrate an ap-l plication of the lter embodying the presentinvention. Y

The actual filtering of the oil is done by a barrel-shaped wire element33 comprising 208 vertical wires per inch of circumference, each 15about ve-thousandths of an inch in diameter and interwoven with 16horizontal wires per inch vertically about seven-thousandths of an linchin diameter. Both Monel metal and phosphor bronze have been foundsatisfactory in use and, of course, other metals may be used.

In making this lter element a rectangular blank 34 (Fig. 4) is cut froma sheet and the Acorners 35 are beveled. The edges 36, 31 and 38, varedipped rst in llux and then in molten solder,

the blank is rolled about a mandrel 39 and the edges 36 and 40 broughtinto overlapping relation on an aluminum strip 4I, after which they aresoldered by applying heat and pressure, as by running a heavy solderingiron along the overlapping edges.

The ends of the barrel thus formed are sealed with two sheet metal heads42 and 43, by folding the marginal portion, as best shown in Fig. 2, togrip what was formerly the edge portions 3 31, 38. The solder that hasbeenl picked up on these edge portions forms beads 44 and 45.`

When the screen is being assembled with the heads, the outer anges 46and 4,1 are spaced bent to the position shown in Fig. 2 by rolling alongthe area indicated by 50, which has the eect of folding the sheet metalabout the soldered bead and leaving the edge 5l slightly spaced from thescreen so that there will be no danger of cutting.A The joint thus'formed is'V practically-'a seal against the passage of oil, orv at leastagainst the passage of any foreign matter sought to be excluded.

'Ihe heads 42 and 43 are held in proper spaced relation by disks 52 and53 of 12 gauge sheet steel threaded on the sleeve I9. In the process ofassembly, disk 52 isfthreaded on the sleeve and locked by the nut 54.. Anut 55 is threaded Qn the lower end of the sleeve and run down againstthe inner portion of the head 43 andv clamped' by a nut 56.

'I'he tube I9-, and parts assembled thereon, forms a unit to be sold incommerce and assembled in suitable casings, which is accomplished in theinstance shown by screwing the lower end of the sleeve into the bore I8,emplacing the shell, and screwing up the cap nut 22.

In operation the oil enters through the inlet 24 and passes into theshell, filters through the wire element 33, runs through the openings 20Cil into the tube I9, and passes to the outlet 21, provided, of course,it is not too viscous to filter, in which case the ball 29 will rise andthe fiow will be shunted directly from the linlet to the outlet.

.In the normal operation, however, with oil in the usual temperatures ofservice, all ow will be through the alter. The so1ia\matr wm, of course,collect against the wires forming the lter element and there will be anappreciable pressure from without, tending to collapse it. This tendencyis resisted in the present instance by a grating 59 formed of 9 gaugesteel wire wound in a helix with the convolutions 11g" on centers.

As the pressure on the inlet side rises the wire element will bendinwardly between the convolutions of the grating 59 andthe corrugatedspring 56 and the head 43 will yieldv sufilciently to make this bendingquite appreciable. Upon the pressure being relieved, however, as forinstance by slowing down or stopping the motor, the wire element willresume its normal position under the reaction of the spring 56 and theinherent resiliency of the head 43, lwith the result that a great dealof the accumulatedforeign matter will be shed and settle down into thesump 26, from which it may be drawn away from time to time by removingthe plug 60.

It has been found in practice that this iiexure and recovery of thescreen throws, oil! about eighty (80%) percent of the accumulatedsludge, hence, the emciency of the screen to pass oil is maintained overa considerable period of use determined by the foulness of the oil andthe volume of the sump.

, The bending of the vertical wires about the convolutions of thegrating tends to localize the strain and relieve lthe joints between thescreen and the heads.

The horizontal (warp) wires 66 are practically straight while thevertical. wires-6l are bent in and out to pass between .each twoadjacent horizontal wires and each vertical wire crosses and contactswith each of two verticalwires next to it. (Figs. to 9 are an attempt toshow the relation on a large scale). Y v The 208 vertical wiresfive-thousandths of an inch in diameter. would actually present acombined width of one and forty-thousandths (1-40/ 1000") when laidparallel and in contact,`

but in the fabric described they are compacted within an inch ofhorizontal width, (the fortythousandths of an inch excess being absorbed.ric are indirect and irregular.

`at the intersections where they each contact is in illtering is aquestion that experts may answer derently and perhaps with conflict. Anattempt to explain the operation in detail might result in error. Theabove description of and the drawings showing the best knownconstruction for use in filtering oil used with internal combustionengines is suicient for this disclosure. Many such lters (hailing abarrel-shaped element 711g" long and 3 in diameter with the by-passadjusted for a pressure differential of 3% lbs. to 4 lbsg) have givenexcellent service with four and six cylinder truckengines.

'Appropriate modications for various uses are contemplated and intendedto be covered.

` We claim as our invention:-

1. In a filter of the type comprising a casing having an inlet and anoutlet and a perforated tube within the casing in communication with theoutlet, the combination of a barrel grating surrounding Athe tube, abarrel screen surrounding the grating and-sustained by the gratingagainst inlet pressure, heads sealed to the tube and the end of thebarrel screen and means for yieldingly resisting the shortening of thescreen barrel.

2. In a filter ofthe type comprising a casing having an inlet ,and anoutlet and a perforated tube within the casing in communication with theoutlet, the combination of a barrel grating surrounding the tube, abarrel screen surrounding `the grating and sustained by the-gratingagainst inlet pressure, heads sealed to the tube and the end of thebarrel screen. one thereof being flexible in an axial direction, thebarrel screen comprising a great many fine wires lengthwise and a smallnumber of fine wires crosswise whereby the passages through it are longand narrow, and spring means for resisting the longitudinal contractionof the screen.

3. In a filter of the type comprising a casing having an inlet and anoutlet and a perforated tube within the casing in communication with theoutlet, the combination of a barrel grating surrounding the tube andhaving continuous cir# cumferential ribs, a barrel screen surroundingthe grating and sustained by the grating against inlet pressure andheads fast on the tube adjacent to the ends of thegrating and sealed tothe ends f of the screen, one thereof being yieldable and spring meansresisting the shortening of the screen.

4. In a filter of the type comprising a casing having an inlet and anoutlet and a perforated tube within the casing in communication with theoutlet, the combination of a barrel grating surrounding the tube, abarrel screen surrounding the grating and sustained,by the gratingagainst inlet pressure, and headswsealed to the tube and the end of thebarrel screen, at least one of the heads being yieldable to tension onthe screen whereby the latter may bend into the passages of the gratingunder the inlet pressure.

and the ends of the barrel screen, and spring means resisting theshortening of the screen.

6. IA commercial unit for filters comprising a central tube perforatedalong the intermediate part of its length, a pair of heads fast on thetube, one beyond each end of the`perforated part,

a barrel screen extending between the heads and sealed to them, thescreen having a multitude of fine longitudinally elongated perforations,a series of circumferential ribs for sustaining the screen againstexternal pressure, and spring means re' sisting the longitudinalcontraction of the screen.V

Q7. A commercial unit for filters comprising a `Wire screen having neWoof strands in juxtaposed relation and relatively widely spaced warpstrands, and resilient means for resisting the screenformed of flexiblematerial; means for di- -rcting the flow through the screen inwardlyaseries of spaced ribs forming a backing for the screen against the inletpressure, and resilient means for resisting inward bowing of the screenbetween the ribs.

9. In an oil ltena casing having inlet and discharge passages, a. filtermember within said casing between said passages, said member comprisinga. screen element of woven wire having an unfolded substantially smoothsurface and having a multiplicity of fine, indirect elongated passagestherethrough, means for resiliently resisting the distortion of saidmember by the pressure'of oil on said surface, and a sump beneath saidlter member. l

10. In an oil fllteya barrel screen of fine woven wire, resilient meansto mount the screen at its

